[google_maps_flutter] Add README section about SDK versions (#11005)

Updates the iOS section of the app-facing package's README to discuss the new `google_maps_flutter_ios_sdk*` packages and how to select between them.

Also removes the Obj-C part of the delegate update example, since at this point it's extremely unlikely that new developers are using Obj-C, and if they are they are making a deliberate choice to do so and so can be reasonably expected to know how to translate to Obj-C.

Fixes flutter/flutter#146920

## Pre-Review Checklist

[^1]: Regular contributors who have demonstrated familiarity with the repository guidelines only need to comment if the PR is not auto-exempted by repo tooling.

Author: stuartmorgan-g

packages/google_maps_flutter/google_maps_flutter/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 2.14.2
+
+* Updates README with discussion of the new `google_maps_flutter_ios_sdk*` packages.
+
 ## 2.14.1
 
 * Replaces internal use of deprecated methods.

packages/google_maps_flutter/google_maps_flutter/README.md

@@ -53,26 +53,7 @@ For more details, see [Getting started with Google Maps Platform](https://develo
 
 ### iOS
 
-1. Specify your API key in the application delegate `ios/Runner/AppDelegate.m`:
-
-   ```objectivec
-   #include "AppDelegate.h"
-   #include "GeneratedPluginRegistrant.h"
-   #import "GoogleMaps/GoogleMaps.h"
-
-   @implementation AppDelegate
-
-   - (BOOL)application:(UIApplication *)application
-       didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
-     [GMSServices provideAPIKey:@"YOUR KEY HERE"];
-     [GeneratedPluginRegistrant registerWithRegistry:self];
-     return [super application:application didFinishLaunchingWithOptions:launchOptions];
-   }
-   @end
-   ```
-
-   Or in your Swift code, specify your API key
-   in the application delegate `ios/Runner/AppDelegate.swift`:
+1. Specify your API key in the application delegate `ios/Runner/AppDelegate.swift`:
 
    ```swift
    import UIKit
@@ -92,8 +73,38 @@ For more details, see [Getting started with Google Maps Platform](https://develo
    }
    ```
 
-2. Read about iOS-specific features and limitations in the
-   [`google_maps_flutter_ios` README](https://pub.dev/packages/google_maps_flutter_ios).
+2. Select an SDK version. The Google Maps SDK for iOS usually releases a new
+   major version once per year, dropping support for an older version of iOS
+   with each major release; see
+   [the SDK release notes](https://developers.google.com/maps/documentation/ios-sdk/releases)
+   for details of the minimum supported iOS version for each release. There is a
+   pub package for each SDK release.
+   - By default, this plugin uses [`google_maps_flutter_ios`](https://pub.dev/packages/google_maps_flutter_ios),
+     which will automatically select the latest SDK release that is compatible
+     with your project's minimum iOS version, up to version 10.x. This
+     functionality relies on CocoaPods, so this implementation is not compatible
+     with [Swift Package Manager](https://docs.flutter.dev/packages-and-plugins/swift-package-manager/for-app-developers).
+     Because the Google Maps SDK [will not be releasing future versions via
+     CocoaPods](https://developers.google.com/maps/documentation/ios-sdk/release-notes#August_18_2025)
+     this implementation will not support SDK releases past 10.x.
+   - To use a specific SDK release, add a dependency on the corresponding
+     package to your `pubspec.yaml` file. All of the SDK-specific packages
+     support Swift Package Manager. In general, you should use the latest SDK
+     release that is compatible with your project's minimum iOS version:
+     - [`google_maps_flutter_ios_sdk9`](https://pub.dev/packages/google_maps_flutter_ios_sdk9)
+       requires iOS 15.0 or higher.
+     - [`google_maps_flutter_ios_sdk10`](https://pub.dev/packages/google_maps_flutter_ios_sdk10)
+       requires iOS 16.0 or higher.
+     - Future major SDK versions will be available as new packages.
+
+   **Important:** Package authors depending on `google_maps_flutter`
+   **should not** depend on a specific implementation package, as that will
+   prevent application developers from selecting the appropriate SDK version for
+   their project. Instead, just depend on `google_maps_flutter` as usual, and
+   leave the choice of SDK version to application developers.
+
+3. Read about iOS-specific features and limitations in the README for the
+   package you selected in step 2.
 
 ### Web
 

packages/google_maps_flutter/google_maps_flutter/pubspec.yaml

@@ -2,7 +2,7 @@ name: google_maps_flutter
 description: A Flutter plugin for integrating Google Maps in iOS and Android applications.
 repository: https://github.com/flutter/packages/tree/main/packages/google_maps_flutter/google_maps_flutter
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+maps%22
-version: 2.14.1
+version: 2.14.2
 
 environment:
   sdk: ^3.8.0